Novel mixed topological state in monolayer MnSbO₃

An important goal of modern condensed-matter physics involves the search for new states of matter with emergent properties and desirable functionalities. In this study, based on symmetry analysis and first-principles calculations, the ferromagnetic monolayer MnSbO₃ was proven to be a quantum anomalous Hall effect (QAH) insulator with a tunable topological state. As the magnetization direction varies in the xy plane, monolayer MnSbO₃ transforms between a QAH insulator with a Chern number C = 1, topological trivial half metal and a QAH insulator with the Chern number C = -1 with a period of 60°. As the magnetization direction is located in the xz plane, the Chern number of the monolayer MnSbO₃ changes between C = ±3 and C = ±1, thereby realizing the regulation of the topological phase. Interestingly, a mixed QAH effect and trivial half-metal topological state occur at the topological phase transition point between two QAH effects. As a result, a mixed topological state was achieved in monolayer MnSbO₃ by regulating the magnetization direction.